Elevator brake



Jan. 17, 1933. w, RUPNOW 1,894,426

' ELEVATOR BRAKE Filed April 22, 1931 2 Sheets-Sheet l W121; p 0w dt mw Jan. 17, 1933. w. L. RUPNOW 1,394,426

ELEVATOR BRAKE Filed April 22, 1931 2 Sheets-Sheet 2 gwmzntot WLHapnow ,fi .6.

{j 1 WW atbmmq Patented Jan. 17, 1933 UNITED STATES WILLIAM L. RUPNOW, OF COLUMBUS, OHIO ELEVATOR BRAKE Application filed. April 22,

This invention relates to an improved brake mechanism especially designed for use in connection with elevators, hoists and other 7 I structures wherein a motor driven drum s provided havin associated therewitha pan of opposed friction shoes which are automatlcally released from 'engagement with the drum upon the energizing and starting of the motor and wherein'means are provjided for automatically applying the friction shoes in braking engagement with the drum when the starting motor is deenergized.

It is an outstanding object of the inventlon to improve upon mechanisms of this type and to provide a simple arrangement of parts for bringing the driven mechanism to a stop quickly and smoothly and without subjecting it to sudden strains or jars.

With these and other ob]ects 1n View, which will appear as the description proceeds-the invention consists in the novel features of construction, combination of elements and arrangements' of parts hereinafter fully I described and, pointed out inthe appended claims. I v In the accompanying drawings: i "Fig. 1 is a view in elevation ofthe brake mechanism comprising the present invention; Fig. 2 is 'a detail vertical sectional view on the plane indicated by the line 2-2 of Fig. 1; Fig. 3 is a similar view taken on the plane indicated by the line 3 -3 of Fig. 1; i

Fig. 4 is a horizontal sectional view taken through the brake mechanism on the line -4: 35 ofFigl; Fig. 5 is a detail horizontal sectional view of the plane disclosed bythe line 5-5 of Fig. 1;

the line 6-6 of Fig. 1.

' Referring more particularly to the drawings, the numeral 10 designates the base or other fixed'portion of the machine to which the brake mechanism, comprising the present invention, isconnected. A. brake drum is indicated by the numeral 11 and is secured'to a rotary shaft 12. In elevator'construction,

this brake drum is vusually a part of a coupling between the'motor shaft and the shaft of the remainder of the hoisting apparatus.

Fig. 6 is a detail-vertical sectional viewon 1931. Serial No. 532,024. I

The frictional brake shoes are indicated at 13-13 and these brake shoes have their central metallic portion'spivotally connected as at 14 with operating arms 15 and 16. The lower ends of these arms'are pivotally secured as at 17 to the base 10, while the upper-ends of said arms are provided with webs 18 formed with perforations which recieve the ends of a transversely extending rod 19. This rod is threaded intermediately of its 5 ends and provided with adjusting nuts 20 and a washer 21. A coil spring 22 ispositioned between the washer 21 and the web 7 18 carried by the arm 15, the normal tendency of'said spring being to force theyarms Fapart whereby to retract the brake shoes from frictional engagement with the perimeter of the dri1m1l. Also, the arms 15 and 16 are provided with transversewebs 23 which engage the inner 'ends of threaded adjusting screws 24, which are carried by brackets 25 integrally formed with the metallic holders of the brake shoes, whereby through the adjustment of the screws 24, the said brake v shoes may be revolved about their pivotal connections with the-arms 15 and 16 to bring the arcuate lined surfaces 26 of said brake shoes into proper registration with the circular faces of the drum 11. i V

Pivotally connected as at 27 with the extreme upper end of the arm 15 is a tie rod 28, which rod hasits opposite end pivotally connected as at 29 with an arcuate weight lever 30. This lever is formed with a suitable enlarged weightproducing portion 31 and the lever as a whole is pivotallycarried as at 32 in connection'with the upper end of the arm 16. Thisconstruction is employed in lieu of springs and other movablemeans for, the purpose of normally serving to maintain the brake shoes in frictional engagementwith the drum 11. By reason of the formation of the arcuate'lever and its weighted. v outer extremity, its tendency is to rock around theaxis 32 so as to impart a pulling force to the tie rod 28, thereby drawing the V brake shoe connected with'thearm l5 into contact with the drum. Likewise, since the lever has a floating 'pivotalmounting on the upon which is mounted a reversible stall motor 34. The armature shaft ofthismotor has secured thereto a pulley to which r is secured the upper portion of a chain or thewall 33.

mediately of its length for the reception of other flexible connection 36. f The lower end of this chain is connected with a bell crank lever 37 pivotally mounted-as at 38. in connection with thewall 33." The shorter arm of the lever 38 is united by means of a link 39 with the lower end of the arcuate lever 30. It will be seen that when the motor 34 is energized, and this is accomplished simultaneously with the operationof the motor used for rotatingthe drum 11, the pulley35 will be partially rotated to draw the chain c011 nection 36 thereabout. This results in rock ing the lever 3.? so that the weight lever30 willbe rocked about its fulcrum32 in such manner as to imparta pushing movement to the tie rod 28, thereby oscillating the arm 15 in such a direction as'to remove the'fric-v tion'al brake connected therewith from con tact with the drum. Similarly,this motion results in oscillating the arm 16 to move the .brake shoe' connected therewith away from the-drum. The motor 34 is preferably em ployed in lieu of a solenoid in that it is very positive and reliable in its operation and does not produce the noise and clatter which is set up by a'solenoid, for example. Further, the motor 34 hasthe ability to remain energized, during the operation of the'main motor, toimpart-a continuous'pull to the flexible connection 36 A dashpot 40 is connected by a link 41 with the bell crank 37 in order to relieve the 'mechanism of sudden strains and jars and to render its action more uniformf 1 Connected with the Web 23' of the arm 16 is a rod 42 which is loosely received in a guide opening formed in the upper end of The rod 42 is threaded interadjustable stop nuts 43, while the outer end of said rod is similarly threaded for the reception of nuts 44. Acoil spring 45 is arranged to surround this rod, between the nuts 44, and the wall 33. v The spring 45 thus supplementsthe action of the spring 22 in drawhbling the brake shoes away from the drum 11 and the nuts'43 are used to adjustablylimit the extent of this withdrawal movement on shown) for rotating the braking drum 11 is energized, the stall mo-tor 34 is simultaneously energized. The rotation of the'shaft of the stall motor partially winds the flexible about its axis 32 on the arm 16 with the result that through the tie rod'connection 28, the

arm 15 and likewise the arm 16.swing about their pivotal connections 17 with the base 10 to withdraw the brake shoes .from contact with the brake druin', thus allowing unh ndered rotation of said drum in unison with themain motor and theconsequent raising and low eringof a car, hoist or other mom ber of the elevator assembly. VVhenthe main driving motor is deenergized,;the stall motor: is likewise deenergized wh ch pernuts the weighted lever 30 to swing by gravityin' V a substantially downward direction,-,whereby the arms 15 and 16 are oscillated, asabove explained, to [firmly contact the friction brakes with the drumll to arrestfurther ro- V tation of said drum and the operationof mechanism connected therewith until the,

main operating motor is again energized. This construction; has the advantage of be- 'ing extremely quiet inoperation, both positiveand reliableand devoidjof small complicated parts which tend readily to become out Order and quire constant repair and ad justment, V V 7 What isclaimedisr Q; 5

1. In elevator brake mechanism, a motor driven drum, a pair of pivotally mounted arms arranged onopposite sides of said drum, brake sho'es pivotally connected with said arms, said brake-shoes being provided with arcuate 1 surfaces adapted for coaction with the perimeter of saiddrum, a weighted lever pivotally connected with the upper end of one of said arms, a tie rod. uniting the other of said arms with an offset portion of.

ans

said lever whereby said weighted lever nor- 9 mally serves through gravity to oscillate said,

arms inwardly to maintain fthebrakeshoes carried thereby n contact with saiddrum, spring means between said arms normally servingto force'said arms apart, said spring means being normally counter-acted; by the weighted lever, a stall motor, a bell crank lever, a flexible connection between;the armatureshaft of said motorand saidbell crank lever, and a link connection between said bell crank lever and thelower depending portion of said weighted lever, whereby when said stall motor is energized, the'said weighted lever is moved to a position against grav- I ityfor effecting the release of the brake shoes.

2.;In elevatorbrake mechanism,:a motor driven drum, pair of pivotally mounted arms arranged on opposite sides of said nected with the upperend of one ,ofsaid drum, brake shoes pivotally connected with said arms, a weightedlever pivotally conwith an oifset portion of said lever whereby said weighted lever normally serves through gravity to oscillate said arm inwardly to maintain the brake shoe carried thereby in contact with said drum, a stall motor, a bell crank lever, a connection between said bell crank lever and the lower depending portion of said weighted lever, a connection between the armature shaft of said motor and said bell crank lever, whereby when said stall motor is energized, the said weighted lever is moved to. a position against gravity for effecting the release of the brake shoes.

3. In elevator brake mechanism, a motor driven drum, a pair of pivotally mounted arms arranged on opposite sides of said drum, brake shoes pivotally connected with said arms, a weighted lever pivotally connected with the upper end of one of said arms, a tie rod uniting the other of said arms with an offset portion of said lever whereby said weighted lever normally serves through gravity to oscillate said arm inwardly to maintain the brake shoes carried thereby in contact with said drum, a stall motor arranged in circuit with the'drum driving motor, and operable means'connecting said stall motor and said weighted lever whereby regardless of the direction of rotation of said stall motor, governed by the rotation of said drum driving motor, said weighted lever is moved to a position against gravity to effect the release of the brake shoes.

4. In elevator brake mechanism, a motor driven drum, a pair of pivotally mounted arms arranged on opposite sides of said drum, brake shoes engaging said drum and pivotally connected with said arms, a weighted lever pivotally connected with the upper end of said arm and functioning through gravity to oscillate said arm inwardly to maintain the brake shoes carried thereby in contact with said drum, a stall motor arranged in circuit with the drum driving motor, an operating connection between the armature shaft of said motor and the lower end of said weighted lever, whereby regardless of the direction of rotation of said stall motor, governed by the rotation of said drum driving motor, said stall motor serves to hold the weighted lever against gravity for effecting the release of said brake shoes.

In testimony whereof I aflix my signature.

WILLIAM L. RUPNOW. 

